III-V Semiconductor Optical Material Data Tool

Optical material properties for ternary and quaternary III-V semiconductors are not included in the default optical Material Database included with Lumerical FDTD, MODE, DGTD, and FEEM. The script files attached to this page provide a tool for calculating the optical properties of various III-V semiconductors and adding the results into the Material Database in FDTD and MODE or the 'materials' folder in the objects tree in DGTD and FEEM.

The material properties are calculated as a function of composition and wavelength using published theoretical models and are added to the Material Database or the 'materials' folder in the objects tree as Sampled 3D Data materials. Multiple models may be provided for a given material.

This page describes the workflow for adding new III-V materials through a GUI and through script and provides a list of available materials and models along with their corresponding references.

Adding New III-V Materials With the GUI

The attached script files provide a GUI for adding new III-V materials:

Note that while this GUI window is open it will not be possible to interact with the other windows, including the main window and plot windows.

To add new III-V materials to the Material Database or the 'materials' folder in the objects tree with the GUI:

1. Download the attached files (found at the top right of this page).
2. Run GUI.lsf. The Compound Material Wizard window should appear.
3. Select a material and model from the Material Database drop-down list.
4. Set the x and y composition of the material. The y field will have no effect if there is no y in the material model name. Both x and y must be between 0 and 1.
5. Set start and stop to the start and stop wavelengths of the generated data and set num points to the number of generated data points.
6. (Optional) Click Visualize to create a plot of the generated material data. The imaginary part of the index will also be plotted if it is included in the model, otherwise only the real part will be plotted.
7. (Optional) Select Visualize benchmark data instead if available and click Visualize to plot the generated material data along with theoretical or experimental benchmark data. The reference for the benchmark data will be given in the title of the plot. If no benchmark data is available for the selected material a plot will not appear.
8. Click Add to add the generated model to the Material Database or the 'materials' folder in the objects tree. The name of the generated material will be the name of the material model with the composition appended to the end. If the model doesn’t calculate the imaginary part of the refractive index it is set to zero.
9. Click Cancel to close the tool.

Note:

• The material models are only valid in a limited wavelength range. The exact range will depend on the model. A warning will appear if the selected wavelength range is outside the recommended range for the model.
• The number of data points should be chosen such that there are enough data points to resolve the features in the material data. The default value of 100 should be sufficient in most cases, though a higher value can be used without drastically affecting simulation speed or performance.

Adding New III-V Materials Through Script

A number of custom functions are defined in the attached script files for creating new ternary and quaternary III-V semiconductor materials and adding them to the Material Database or the 'materials' folder in the objects tree. Running the script III_V_index_models.lsf will define these functions, allowing you to use them in your own scripts.

To add new III-V materials with this tool through script:

1. Make sure the working directory is set to the root directory of the provided files.
2. Run the script III_V_index_models.lsf. This can be done in a script with the command III_V_index_models; if the script file is in the working directory.
3. Create the material index values with the getmyindex function.
4. Add the material with the add_my_material function.

The script file scripted_commands_example_without_GUI.lsf included with this tool provides an example of how to create new materials with this scripted approach.

Function Syntax

The syntax for the script functions getmyindex and add_may_material is described below.

Available Materials

The following table lists the available materials and their corresponding models provided with this tool:

For a material lattice matched to InP, the material "In(1-x)Ga(x)As(f(x))P(1-f(x))" has a y that depends on the function \(f(x)\), given in "S. L. Chuang, Physics of Optoelectronic Devices":

$$y = f(x) = \frac{0.4184x}{0.013x + 0.1894}$$

Material Models

The optical index models included in the database are taken from reliable and benchmarked sources cited below. New models can be added upon user request.

default

This model is available for most materials as it is based on interpolation of material properties such as band gap from binaries (for ternaries) and from ternaries (for quaternaries). However, it may not always be the most accurate, so it is recommended to use other models if they are available and only use this model if there are no other models available.

In deciding which model to use the user may also first plot the benchmark data, if available. The model is derived for photon energies up to the band gap and it is usually a good approximation for energies slightly above the band gap, but it should be used with care for photon energies much above the band gap.

Reference: Guden and J. Piprek, "Material parameters for quaternary III-V semiconductors for multilayer mirrors at 1550 nm wavelength", Modelling Simul. Mater. Sci. Eng. 4 (1996) 349–357.

adachi

This model is the same as default, but with slightly different values for some parameters used in the interpolation.

Reference: Adachi, "GaAs, AlAs, and AlxGa1-xAs: Material parameters for use in research and device applications", J. Appl. Phys., 1985, 58, 3, DOI:10.1063/1.336070.

alam

This model is the same as default, but with slightly different values of some parameters used in the interpolation.

Reference: Alam, M. S., Rahman, M. S., Islam, M. R., Bhuiyan, A. G., and Yamada, M., "Refractive Index, Absorption Coefficient, and Photoelastic Constant: Key Parameters of InGaAs Material Relevant to InGaAs-Based Device Performance", 02 July 2007, 2007 IEEE 19th International Conference on Indium Phosphide and Related Materials, DOI:10.1109/ICIPRM.2007.381193.

ivanov

Reference: Ivanov A. V., Kurnosov V. D., Kurnosov K. V., et al., "Refractive indices of solid AlGaInAs solutions", Quantum Electronics 37 (6) 545, 2007, DOI:10.1070/QE2007v037n06ABEH013442.

kaneko

Reference: Kaneko and K. Kishino, "Refractive indices measurement of (GaInP)m/(AlInP)n quasi-quaternaries and GaInP/AlInP multiple quantum wells", J. Appl. Phys., 1994, 76(3): 1809-1818.

kato

Reference: Kato, S. Adachi, H. Nakanishi, and K. Ohtsuka, “Model dielectric function (MDF) for (AlxGa1-x)0.5In0.5P latticed matched to GaAs”, Jpn. J. Appl. Phys., 1994, 33(1R): 186.

seifert

Reference: Seifert and P. Runge, "Revised refractive index and absorption of In1-xGaxAsyP1-y lattice-matched to InP in transparent and absorption IR-region", Opt. Mater., 2016, 6(2): 629-639.

Models With Imaginary Refractive Index

Some models include the imaginary part of index, but not all. The models with nonzero imaginary parts are: "(AlxGa1-x)0.5In0.5P::kato" and "In(1-x)Ga(x)As(f(x))P(1-f(x))::seifert".

The models without imaginary parts are typically created for photon energies up to and around the band gap, where the imaginary part is still small. Some application areas for these models are:

• Simulation of light generation devices. These devices operate around the band gap and the imaginary part of index is dominated by gain (or exciton absorption) and free carrier absorption, which are calculated separately from the bulk index model. Here, you can successfully use these index models to calculate the effective and group index and the mode confinement factor. For example, look at step 1 in this edge emitting laser application: example Self-heating in AlGaInAs-InP multi-quantum well (MQW) laser – Lumerical Support, or this electro-absorption modulator example: GaAs-AlGaAs Electro Absorption Modulator – Lumerical Support.
• Simulations for photon energies up to the band gap, or best-case results for higher photon energies.